When a Ruti L-5000 weaving machine is used in conjunction with a Staubli dobby head, a pattern defect can be caused by improper operator technique. The Staubli head is a device used to control the weaving pattern of the cloth by means of a rotating pattern chain. It has a control lever that can be placed in several positions. The positions used most frequently during normal operation are RUN and REVERSE. Other positions exist but are used less frequently and deal mainly with loom set-up. The RUN position is used for normal operation.
The REVERSE position is normally used when correcting a loom-stopping defect, i.e., in trade terms, "matching the pick". During this correctional procedure the operator can create an additional pattern defect unless the proper technique is used.
While the Staubli pattern chain movement is controlled by the lever, loom movement (rotation) is controlled by a separate means. Button-activated switches allow the loom to be started, stopped, forward jogged or reverse jogged. Proper technique requires that the direction of loom movement be correlated with the setting of the Staubli lever. Quite simply, this means that if the operator pushes the wrong movement button while the Staubli is in a particular setting, a pattern defect can be caused that will be seen when the loom is started. This has previously been prevented to a degree through operator training. However, errors still occur, creating fabric defects.